import React, { Component } from 'react'
// 引入store，用于获取redux中保存的状态
import store from '../../redux/store'
// 引入actionCreator，专门用于创建action对象
import {
  createIncrementAction, 
  createDecrementAction,
  createIncrementAsyncAction
} from '../../redux/count_action'

export default class Count extends Component {

  /*componentDidMount() {
    // 检测redux中状态的变化，只要变化，就调用render
    store.subscribe(() => {
      console.log('@')
      // this.render() xxx
      this.setState({})
    })
  }*/

  increment = () => {
    const {value} = this.selectNumber
    store.dispatch(createIncrementAction(value*1))
  }
  decrement = () => {
    const {value} = this.selectNumber
    store.dispatch(createDecrementAction(value*1))
  }
  incrementIfOdd = () => {
    const {value} = this.selectNumber
    const count = store.getState()
    if(count % 2 !== 0) {
      store.dispatch(createIncrementAction(value*1))
    }
  }
  incrementAsync = () => {
    const {value} = this.selectNumber
    // setTimeout(() => {
      store.dispatch(createIncrementAsyncAction(value*1, 1000))
    // }, 1000)
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{store.getState()}</h1>
        <select ref={c => this.selectNumber = c}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;&nbsp;
        <button onClick={this.increment}>+</button>&nbsp;&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;&nbsp;
        <button onClick={this.incrementIfOdd}>increment odd</button>&nbsp;&nbsp;
        <button onClick={this.incrementAsync}>increment async</button>
      </div>
    )
  }
}
